Answer:

' Tuning Fork Program
'
PRINT "Enter the frequency (37-32000):"
INPUT FREQ
IF  FREQ >= 37 AND FREQ <= 32000 THEN
  SOUND FREQ, 18
ELSE
  PRINT "Frequency is out of range"
END IF
'
END

Range Testing

Here is what happens when the user enters a FREQ that is too low, 20 for example:

FREQ >= 37 AND FREQ <= 32000
----------      ----------
   false    AND      true
     ------------------
           false
            

FREQ must meet two requirements at the same time:

On a "number line" this looks like this:

............+--------------------------------+....................>
0           37                           32000
                FREQ must be in this range

To check that FREQ is in the required range you have to use two relational expressions: one to check that FREQ is not too low, another to check that FREQ is not too high. Then the two are combined with AND, since both tests must be passed.

QUESTION 9:

Fill in the blanks in the following IF statement so that the true branch will execute when X is in the range of 100 to 200, inclusive. In math this is written: 100   <=  X  <=   200.

IF ________________________  AND _____________________  THEN